Sunlight is required for photosynthesis to take place. Organisms use only a small range of
wavelengths for photosynthesis, vision, and other processes. Most of these wavelengths are the ones
we see as
visible colors. Light energy is packaged as photons, which vary in energy as a function of
wavelength.
Several kinds of photon absorbing pigment molecules are found in plants.
Chlorophyll pigments absorb blue and red light but transmit green accounting for the color of
leaves. In thylakoid membranes of chloroplasts, pigments are organized in clusters called
photosystems, each consisting of 200-300 pigment molecules.
Carotenoid pigments absorb violet and blue but transmit yellow, orange, and red.
Phycobilins are red and blue pigments found in red algae and cyanobacteria. Cyanobacteria have
chlorophyll a and other pigments in some internal foldings of their plasma membrane.
Several kinds of photon absorbing pigment molecules are found in plants.